Rotatable breech-bolt for automatic firearms.



P. MAUSER, DECD.

r. EICHHORN, ADMINISTRATOR. ROTATABLE BREECH BOLT FOR AUTOMATICFIREARMS.

APPLICATION FILED DEC. 1. 1914.

Patented Apr. 25, 1916.

lllllllljj UNITED STATES PATENT OFFICE.

PAUL MAUSER, DECEASED, LATE OF OBERNDORF-ON-THE-NECKAR, GERMANY, BY

5 FRIEDRICH EICHHORN, ADMINISTRATOR, 0F OBERNDORF-ON-THE-NECKAR, GER-MANY, ASSIGNOR TO WAFFENFABRIK MAUSER AKTIENGESELLSCHAFT, 0F OBERN-DORF-ON-THE-NECKAR, GERMANY, A CORPORATION OF GERMANY.

Specification of Letters Patent.

ROTATABLE BREECH-BOLT FOR AUTOMATIC FIREARMS.

Patented Apr. 25, 1916.

Application filed December 1, 1914. Serial No. 875,051.

To all "whom it may concern Be it known that PAUL Mimsnuydeceased, latea subject of the King of Vurttemberg and residing at ()berndorf-on theNeckar, in the Kingdom of Wurttemberg, Germany, invented certain new anduseful Improvements in Rotatable Breech-Bolts for Automatic Firearms, ofwhich the following is a specification.

This invention relates to a further development of the rotatable breechbolt for automatic fire arms with fixed barrel shown in an applicationof the said Paul Mauser filed February 12, 1914, Serial No. 818,235,wherein a positive locking is attained in that the breech bolt havingthe nipples cooperates with a longitudinally movable locking part. whichin the locking position and by the controlling of the nipples locks thebreech bolt against rotation and is re leased from its locking positiononly by the shot.

The subject matter of the present inven-' tion relates to thearrangement wherein the locking part does not lock the breech boltdirectly but through the medium of a pawl inserted between the lockingpart and the breech bolt, such pawl in its inner position controllingthe movement of the bolt nipples and being positively rocked inwardlyand outwardly bythe locking part in its longitudinal movenient.

This improvement is shown in the accompanying drawing.

Figure 1 is a plan of the breech bolt with its parts in the lockingposition, the pawl being disposed inwardly and the rod controlling themovements of the pawl in the locking position. Fig. 2 is a frontelevation. Fig. 3 is a side elevation to Fig. 1. Fig. 4 shows theposition after the shot with outwardly disposed pawl and advanced rod.Figs. 5 and 6 are plan and interior views respectively of the slidingcontrol-rod.

According to this invention, the breech bolt .70 carries the bolt head'0 with the rotatable or locking nipples Q0, while the locking parts,which effect the positive locking, cooperate with the bolt head T. Forthe maintenance of the gas-tight breech bolt while the projectile isstill in the barrel, there is provided a pawlt which is pivoted behindthe bolt head to the breech bolt and is controlled in its action by thelongitudinally movable rod 8. .In the locking position of the parts i.e. before and during the firing, the nipple w is controlled by the frontarm of the pawl provided with a bevel t the rod 8 is now in the rearwardposition, so that it secures with its inwardly bent head 3 the arm ofthe pawl in its controlling position. The rear arm of the pawl t has aproj ection 25 which bears within a longitudinal recess 3 of the rod 8'.If, after the firing, the rod 8 advances through its inertia, its head8' will relase the arm of the pawl; owing to the action of the camsurfaces in the recess .9 of the rod 8 on the projection t of the reararm of the pawl, the pawl is actuated in such a manner that its frontarm is rocked outwardly clear of the nipple w, whereby the bolt head isreleased for rotation. The projectile has then left the barrel and theunlocking as well as the backward movement of the breech bolt can takeplace normally under the action of the existing pressure. The rod 8 isprovided with an upwardly disposed push button 8 for being operated byhand when loading for the first time so that the advancement of the rod8 and the return of the breech bolt can be effected by a grip with theright l1 and. 7

What is claimed is:

1. A breech mechanism for fire arms, comprising a brcech piece, saidbreech piece having a rotary part having locking lugs thereon, and meansfor locking said breech piece in position to close the breech, saidmeans comprising a part on said breech piece adapted to move into andout of position to prevent rotation of said rotary part, and an inertiapiece adapted to retain said locking part on the breech piece in lockingposition.

2. A breech mechanism for fire arms, comprising a breech piece, saidbreech piece having a rotary part having locking lugs thereon, and meansfor locking said breech piece in position to close the breech, saidmeans comprising a part on said breech piece adapted to move into andout of position to prevent rotation of said rotary part, and an inertiapiece adapted to retain said locking part on the breech piece in lockingposiposition, and the incline of the gro ves bemove on recoil of thefire arm ing a part on said breech piece adapted to move. into and outofposition to prevent rotation of said rotary part, and an inertia pieceadapted to retain said locking part on the breech piece in lookingposition, said in ertia piece being adapted to move on recoil of thefire arm out of position to retain said locking part on the breech piecein locking ing such that the pressure of the ga in' the fire arm issuflicient toturn said rotatable part of the breech piece in saidinclined grooves and open the breech.

4. A breech mechanism for fire arms including a breech piece; saidbreech, piece having a rotary part having lugs thereon, and means forlocking said breech piece in position to close the breech, said meanscomprising a part pivotally mounted on the breech piece adapted to moveinto and out of position to prevent rotation of said rotary part, and aninertia piece adapted to retain said pivotally mounted part inlocking-position, said inertia piece being adapted to move on recoil ofthe fire arm out of retaining position. v

5. A breech mechanism for fire arms comprising a breech piece, saidbreech piece having a rotary part having locking lugs thereon and meansfor locking said breech piece in position to close the breech, saidmeanscomprising a two armed lever pivotally mounted on the breech piece, onearm of which is adapted to move into and out of position to preventrotation of said rotary part, and an inertia; piece adapted to retainsaid lever in locking position, said inertia piece on \recoi'l of thefire arm being. also adapted to contact with one arm of said lever tomove sald lever out of locking position.

6. A breech mechanism for fire arms com-' prising a breech piece saidbreech piece having a rotary part having locking lugs there on, andmeans for locking said breech piece in position to close the breech,said means comprising a part on i-said breech piece.

adapted to move into and rout of position to preventrotation of saidrotary part.

' 7. A breech mechanism for firearms comprising a breech piece, saidbreech piece having a rotary 'part having locking means thereon, andmeans on said breech piece for locking said rotary part against rotatiom8. A breech mechanism for fire arms comprising a breech piece,; saidbreech pie'oehav ing a rotaryv part having locking means thereon,- andmeans on said breech piece forff locking said' rotar part againstrotation, and an inertia part controlling the action of said lockingmeans.

9. A fire arm comprising, a" breech bolt having a rotatable'part,andmeans for preventing rotation of said' rotatable part, said meanscomprising a pawl adaptedto engage the rotatable part and an'inertiapartcon-' trolling the action of said pawl.

, 10. A fire arm compri ing a breech bolt having a rotatable part, andmeans for preventing rotation of said rotatable part, said meanscomprising a pawl adapted to engage the rotatable part and aninertiaslide having a. projection adapted to engage behind said pawl andadapted to move from behind said pawl under the force of inertia.

11. A fire arm comprising abreech bolt; having a rotatable part, andmeans for pre venting rotation of said rotatable part, said meanscomprising'a pawl adapted to engage the rotatable part and an inertiapart controlling the action of said pawl, said inertia part having meansfor positively moving said pawl to releasing position. I d

12. A fire arm comprising a breech bolt,

said breech bolt having a rotatable and a non rotatable part, means forpreventing rotation. of said rotatable part, said means comprising. apart carried by the non-rotatable part of said breech bolt.

In witness whereof, I have hereunto signed my name in the presence oftwo subscribing witnesses.

FRIEDRICH EICHHORN, Administrator of the estate of Paul M auser,

deceased.

n I W1tnesses ER'NnsT- ENTENMANN, FRIDA KLAIBER.

